Boring machine



Feb. 25, 1947. w. F. MITCHQELL 7 2,416,402

' BORING MACHINE Filed Sept. 29, 1944 3 Sheets' -Sheet 1 Feb. 25,1947. w, F MITCHELL 2,416,402

BORING MACHINE Filed Sept. 29, 1944 a Sheets-Sheet 2 IN V EN TOR.

g lflaflapelWiic/zel BY J Wm WM Feb. 25, 1947. I w MlTCHELL 2,416,402

BORING MACHINE Filed Sept. 29, 1944 s Sheets-Shet 5 figam",

INVEIIVTOR. w l J ZZ/QZZaceF/YLzc/zd BY 7 v I 52 m fw y m M I eters.

Patented Feb. 25, 1947 UNI' TED ST ATES PATENT OFFICE- BORING MACHINE 'Wallace F. Mitche'll, Chicago, 111., assignor to Ammco Tools, Inc., a corporation of Illinois Application September 29, 1944, Serial No. 556,3'12

'6 Claims.

' garages.

Another object is to provide a novel boring machine for boringbearings of the foregoing character, which machine is-of such construction that it may be classed as a portable machine and thus :is of particular use in a shopsuch as an automobile repair shop for reboring the crank pin hearings of connecting rods as an incident to the overhauling and reconditioning of automobile engines.

It is also an object to provide a machine for a boring connecting rod bearings, which :may be made solely for boring work of such character or which may be incorporated in a machine for boring the bearings of an engine cylinder block.

.A further object is to provide a novel machine for boring connecting rod hearings, in which the connecting rod may be clamped with its bearing accurately aligned with the boring .bar and the boring tool fed through the bearing in a positive and uniform manner.

Still another object is to provide .a machine for boring connecting rod bearings, which may be easily set up for the boring operation, in which the connecting rod may be readily clamped in proper-position, and in which the boring operation may be readily performed with a .hjighdegree of accuracy.

A still further object is to provide a novel ma- "chine for boring connecting rod bearings, which .is readily adaptable for connecting rods of various size and having bores of various diam- Other objects and advantages become apparent from the following description taken in connec --tion with the accompanying drawings, in which: Figure 1 is .a fragmentary perspective view of a machine embodying the features of the inven- ;.'tion and incorporated as apart of a machine for horing the line v bearings of a cylinder block.

551; Fig. 2 is an enlarged fragmentary end elevational view'of the machine shown in Fig. l.

Fig. 3 is an enlarged fragmentary side eleva- ;tiona1 view, partially in section, and showing the manner .in which .a connecting rod is supported in the machine shown in Fig. l.

Fig. 4 is a horizontal sectional view taken .on.

the line -4,-4 of Fig. 3. I

5 is a perspective view of another form of the machine.

Fig. .6 is a fragmentary end elevational view of the machine .shown in .Fig. 5.

Fig. I is a fragmentary plan view of the .machine shown in Fig. 5.

The present applicationis a continuation-inpart of my copending application Serial No. 479,579, filed March .18, 1943, which became .Patent No. 2,401,838 of June 11, 1946.

A machine having the .ieatures of the present.

invention maybe and is here shown as embodied in two different forms, one form being .such that it is incorporated in .a machine for boring the linebea-rings of a cylinder block .for an automobile. engine, as shown in Figs. 1 to 4, inclusive, andv the other form being adapted to be mounted in some suitable position as in a vise 0n awork bench.

The present machine in each of its .forms com-- prises generally a supporting structure in which a boring bar is mounted .both for rotation and .for longitudinal feeding movement. The supporting structure is provided with means by which connecting .rods of various sizes may be clamped concentrically withthe boring bar so that the crank. pin bearings of. such connecting rod may be accurately rebored. .Thus, the machine includes means for clamping the connecting rod in accu rate alignment with the boring bar, and the boring tool may be fed throughv the bearing of the. connecting rod in a positive and uniform manner. Both of the embodiments ofthe invention herein disclosed provide a machine. particularly adapted for use in automobile repair shops and provide. a convenient means for refinishing the crank ,pin bearings of the connecting rods as an incident to the overhauling and reconditioning of automobile engines. 7

As mentioned above, the form 'of machine shown in Figs. .1 to 4 .of the drawing is such that reboring of connecting rods may be performed on and by .a .machine designed for boring line bearings, such as thecam and crankshaftb'ear ings in the cylinder block of an internal combustion engine. In the particular form of construction shown in these figures, the machine is of such character that it .is adapted to be mounted directly on such a cylinder block and to be carcylinder block. The. boring operation is adapted to beperformed with the caps of the various bearings and, the bearing-inserts in assembled-rela tion with the cylinder block without necessitating their removal.

The machine comprises a pair of parallel rails l3 and I4 adapted to be mounted on the pan rails l2 and 1 secured thereto by means, such as,

C-clamps, one of which is shown at I5. The

clamps l5 thus hold the rails rigidly on the cylinder block and in spaced, parallel relation to each other.

shown at [6, rigidly, secured to the rails as by screws l! in spaced relation along the rails. Pref erably, the bridge members (6 are so located'that there is one'of them at each end of the rails beyond the ends of the cylinder block and other bridge membersare located intermediate the line bearings of the cylinder block to .provide rigid supports therebetween.

Rotatably carried by the bridge members is a; boring barZO extending through the various bearc I 130 The'boring'bar 20 is supported by each of-the' bridge members l6, and to this end each bridge ings I I and beyond the ends of the cylinder block.

member is provided with an upright 2| adjust- However, when the upright 2| is so passed through'the ball-like member [6, the segments of each member are clamped tightly against the upright in such a way as to insure a uniform clamping action for all segments without distortion of the unit and boring bar carried thereby. The clamping means employed is such as to provide a positive and firm clamping or locking action upon but slight pressure bythe operator. V

This clamping action is accomplished by an I -gadiustable clamping nut I 6 so located that its axis extends substantially parallel with the axis 7 of the boring bar 20. This nut is threaded for Connecting the rails l3 and I4 is a plurality of bridge members, two of which are ably mounted'in the bridge member and provided with means such as bearings 24 and 24a at its lower end for rotatablysupporting the boring bar 20. In setting up the machine, after the rails 13 and I 4 are clamped to the cylinder block and the bridge members [5 are secured to the rails by the screws [1, the boring bar 20 is pref- 1 erably aligned or centered with the two end bearings of the cylinder block by means of a centeni'ng device such as shown in my parent applica- 1 tion. When'the boring bar is so centered, the

uprights 2| of the two end bridge members are 1 then clamped in place to rigidly hold the boring bar in its aligned position. Thereafter, the uprights 2| of the intermediate bridge members are clamped in place to support the boring bar 1 in the position determined bythe uprights 2| of 3 the two end bridge members.

" The boring bar support above referred to in- I I the boring bar willbe supported in such a mane 1 ner as to bore all of the aligned bearings of the 1 cylinder block in true axial alignment with each 1 other.

"The foregoing structure is fully described in A segmental tubular ballupright '2|-,,the ball-like memberclfi being con-- fined against the seats [6 and I6 for a ball-like universal action; j As explained in my "parent application, the segments of'the ball-like member lfi are yieldingly spread apart by suitable springs so that they are normally held against the seats lii 'and'lli with; the segmental-parts thereof sprung apart to an extent to permit the upright member 2| to pass freelytherebetween.

I cludes a universal connection between the bridge member l6 and the upright 2l which permits of 1 relative vertical and angular displacement so that reception in a threaded opening in the body of the bridge member IS with its inner end engaging (but not fastened to) a so-called compression plug l6 having at its inner end a conical seat It which engages the adjacent spherical surface of the adjacent one of the'segments of the ball member I6. The plug 16 is a floating member, so to speak, permitting it to adjust itself to the engaged segment without a cramping action which would tend to distort the setup. Though this plug is floating and free to adjust itself as stated, it is prevented from displacement rotatively when the clamping nut "i is set up by a pin [6 carried by the bridge member l6, which pin extendsintd' an enlarged opening Iii in the adjacent wall of the plug N5 'The opening [6 is large enough to permit sufficient play in the plug l5 to permit" 7 of the adjustment above referred to while avoiding any torsional effects that would tend to dis} tort in the setting up of the plug I6 With the foregoing arrangement, when the plug IE is tightened, the segments of the ball-like member it are uniformly moved towardeach other and the upright 2| to efiect a clamping action and, since the force applied through the plug I6 is in a direction parallel'withthe axis of the boring bar 20 and at right angles to the axis of the upright 2|, all tendency to laterally distort the boring bar. 20 is avoided.

Furthermore, to insure a uniform and positive clamping action between'thesegments of "the ball-like member l6 and the upright 2|, each of the segments of the member I6 is provided on its 'inner 'face with spaced-apart bearin'g'surfaces I6 so that each segment engagesthe uprighttl" at spaced-apart points substantially in alignment with the ball seats l6 and Ili'i; Thus the segments of the ball-like member It always clampingly= engage the upright 21 at spaced-apart points and at direct pressure-applied points, thereby insuring a multiple clamping engagement upon the tightening of the plug I6 It will be seen that when the plug l6. is-tightenedf the segments of the ball member 16 not directly engaged by the plug l6 are brought into tight clamping engagement with'the seat surfaces lfi and l6 while the segment engaged by the'plug Iii ismoved away 'from'such seats when the segments are brought together and contracted upon the upright 2|." At'this time the support normally afforded the latter segment by the seats 15 and Iii is now provided by the conicalface of the compression plug lfi 'so that all of the segments are fully and firmly supported with anequalized pressure applied substantially throughout the circumference of not only the ball support butthe uprightllg Such equalization of pressure avoids distortion of i any of the parts involved which might be transmitted t'o the bdring bar and cause inaccurate boring.

The boring bar 29 is providedwith a pluralityof apertures (not shown) at spacedpoints along its length to receive a radially extending :boring correct diameter, by means of a micrometer set-' ting device such as is disclosed in Serial No. 522,764, filed February .17, 1944, which is a division of my parent application.

The foregoing brief description of the machine shown in Figs. 1 to 4, inclusive, discloses the nonstruotion thereof when the machine is adapted for boring the line bearings :of a :cylinder block. However, such machine maya'lso be constructed so that the crank pin bearings of connecting rods may be bored while'the machine :is mounted upon the cylinder block Ill. For this purpose, the end bridge member 1]5 supports an "upright 2| which is provided with'means for clamping a connecting rod thereto in concentric relation with the :boring bar 20. Thus, as shown in Figs. 1 to 4 of the drawings, the upright 21 in the end bridge member' I6 is provided on its lower end with means for supporting the boring bar at axially spaced points. As shown herein, the lower end of the upright 2| is provided with a laterally extending head 23 shaped to provide a pair of bearings 24 supporting the boring bar 20 at axially spaced points. The bearings 24 are preferably split, as at 25, at one side so that the two sides of the split in each bearing may be drawn together, as by a screw 26, to firmly hold the boring bar in a properly-centered position. .As mentioned above, such centering of the boring bar is performed during the mounting of the machine on the cylinder block.

.For the purpose of supporting a connecting rod in concentric relation to the boring bar, the outer bearing 24 is provided with a flange 30 to which a face plate member 3| is rigidly secured, as by screws 32. The face plate member 3| is annular in form and has a face 3|a normal to the axis'of the bearing 24 and an internal diameter 34b adapted to receive a face ring 33 against which the connecting rod is adaptedto be clamped. The face .ring 33 has an outwardly extending flange 34 adapted to lie flat against the outer face of the face plate member 3| and providing .a surface transverse to the axis of the boring bar, against which one face of the connecting rod bearing abuts to hold the latter in proper position. It is contemplated that a plurality of face rings 33 will be provided for the machine, with the face rings having different internal diameters to provide for a plurality of sizes of connecting rods, thus providing a surface against which connecting rods of. various sizes may be radially clamped. 'In each case, however, theinternal diameter of the face rings 33 is of slightly larger size than the diameter of the bearing in the connecting rod to be bored, so that the boring.

tool inmoving through the connecting rod bearing will not contact the face ring 33.

To clamp the connecting rod against the-face ring 33, theface plate member 3| is provided with a pair of radially extending ears 35 to support a pair of threaded rods 36 in parallel relation to the boring bar 28. Preferably, the ears 35 are positioned diametrically opposite each other.

Slidably mounted on the threaded rods 36 are clamping members 40, each comprising-a hub portion mounted on the rod 36, and a radially extending arm 4| provided at its free end with a boss- 42 to abut against the outer "face nf-the connecting :rod and clampit against the flange 23-4 of the .face :ring '33. The clamping members 4:0 are held rigidly :in clamping relation with the connecting red by means of elongated hexagonal nuts 43 threaded :on the outer ends of the "rods 36.

use, the machine is set up upon the cylinder :block I10 .as heretofore described. When it is desired to utilize the machine for boring a connecting :rod, a face :ring 33 of a .size suitable for the particular connecting rod to be bored is mounted in the face plate member 3|. The connecting :rod is then placed over the boring bar 20 Bin abutting engagementwith "the end face of the flange 3'4 of the faceri-hg 33, and thebearing of the connecting rod is then aligned or centered with the boring :bar by means of a centering device such :as shown inmy-paren't application and my .Patent'.-No. 2,391,183., issued December '18; 1945, .on application Serial No. 522,765, filed Feb ruary 17., 1944, as azdivision of said parent .appli-, cation. When the bearing of the connecting rod is so centered, the clamping members 40 are tightened by means :of the nuts 43 against the outer face of the connecting rod .to rigidly clamp it against the face ring 33. Theclamping :members 40 being 'slidable :on the rods 36 provide for clamping of connecting rods having different lengths of bearings, and by swinging the clamp ing members 4 0 on the rods 36, the bosses:

thereof may be swung about the axes of the rods 36 so that connecting rods having bearings of varying diameters may be rigidly clamped in proper position.

After the connecting 'rod has been .so clamped in position, the boring tool :01 bit .22 is set :to the proper radial distance to bore the correct diameter in the bearing of the connecting-rod, by means of a micrometer setting device such as disclosed in Serial No. 522,764, filed February 17, 1944, which isa division of my parent application.

With the boring tool so set, the boring operation may then be performed by 'rotatably driving the boring bar '29 and feeding it longitudinally tomove the tool through the bearing of the com necting rod, the means for rotating the boring bar and for feeding it not being shown herein but being fully disclosed in my parent application.

In the embodiment sh'ownin Figs. 5, 6 and 7, the machine is of substantially the same character as shown in Figs. .1 to 4, inclusive, except that, instead of being incorporated as part of a machine for boring the line bearings of a cylinderblock, it is of unitary character adapted to be mounted on a work bench. To this end, the

machine shown in these figures includes supporting s'truc'turecomprising an'upright adjustably clamped in a block 5|. The block 5| is of suitable form to be readily gripped in the jaws of a vise 52 of the character commonly found in automo-' bile repair shops. In its preferred formythe block 5i comprises an elongated portion adapted to be clamped between the jaws of the vise and to extend sidewarclly therefrom with an enlarged head 53 bored to receive the upright and split so that the head 53 may clamp the upright-as by tightening screws 54. Theupright 50 iso'f substantial length so that it may be vertically adjusted to bringthe machine in a convenient position for the operator, the lower end of the upright being provided. with a collar 55 to prevent the supporting block '51 "from sliding off the uprightwhen the block is removed from'the vise.

The upper end of the upright 5c is provided" with a head 56 having a pair of longitudinally spaced bearings 5'! in "which "the boring bar, herer 7 indicated at 60, is adjustably supported. The bearings 51 are split so that the parts thereof may be drawn together, as by screws Bl, to hold the boring bar in accurate alignment therewith.

One of the bearings 5'! is provided with a flange G2 to support a face plate member 63 of the'same construction as shown inthe previous form of the machine. The face plate member 63 is provided with a face ring and clamping means similar to those shownin'Figs. lto 4, inclusive. i

- To effect rotation of the boring bar, the end thereof opposite the end carrying the boring tool may be provided with a hand crank 64 by which it may be rotated or an electric power drill '(not.

shown) may be'secured thereto to efiect rotation of the boring'bar.

The end of, the'borin'g bar carrying the hand crank 64 is also provided with a feed device'65 of the character disclosed in my parent application and a division thereof, Serial No, 553,320, filed September 9, 1944. Such feed device is carried on the boring'bar and is adapted to efiect longitudinal feeding movement of the bar during rotation thereof so that the boring tool will be moved through the bearing of. the connecting rod to effect boring thereof; The feed device 65 is provided with a feed bar 65 adapted to be connected to a fixed part of the machine to provide'for the longitudinal feeding movement. Preferably, such feed bar 66 is connected to a lug 67 formed integrally with the adjacent bearing 5! in a manner similar to that disclosed in myparent application and a division thereof, Serial No. 553,320, filed September 9, 1944, x

Innsing themachine shown in Figs. 5, 6 and 7, the block 5| is first clamped. in the vise 52. The

screws 54 in the block 5| are then loosened and the upright raised orlowered to bring the various parts of the machine in convenient posie tion for operation, thescrews 54 thereafter being tightened to clamp the upright in place. The boring bar is then centered in the bearings 51 by tightening the screws 6| thereof. The machine is now ready for mounting the connecting rod thereon and, preparatory thereto, the proper sizeface ring is selected and placed in the face plate member 53. The connecting rod is slipped over machine is thereby made ready for operation,

which iseffected byrotating the boring bar by means of the hand crank 64 or an electric drill, with thefeed device 65 eifectinglongitudinal feed of the boring bar to move the toolaxially through 'the connecting rod bearing.-

' From the foregoing descriptiomit will be apnecting rod bearing. The work performed by the machine is highly accurate since the boring bar is rigidly held in alignment with the supporting bearings of the machine and the connecting rod is rigidly clamped in the machine and accurately held in concentric relation with the boring bar. The boring tool may be accurately set to bore thedesired diameter and the boring bar may be conveniently rotated to effect the cutting action either through the hand crank 64 or by an elec-- trically operated drill, the feeding of the boring barbeing effected by means of the feed device 65.:

I claim:

1; In a boring apparatus comprising a boring. 7 bar, bearing means for said boring bar and sup-'. porting means for said bearing means, the provision'bf a further b'earingmeans adaptable to said boring bar, said ifurther bearing means being adjustable to fit and-center it accurately on said' boring bar, universal connecting means having a portion secured to said bearing means and a portion securable to said supporting means, and a connecting rod supporting means rigidly secured to said further bearing means.

2. In a boring apparatus comprising a'boring 2' bar, bearing means for said boring bar and sup-" parent that I have provided a novel machine for reboring the crank pin bearings of connecting rods of the type utilized in internal combustionv engines. The machine may be of a formadapted; to be incorporated in and as a part of 'a machine for reboring the aligned bearings of a cylinderblock, as shown -;in Figs. 1to 4, or maybe a sepaporting'means for said bearing means, the pro-' vision of a further bearing means adaptable to said boring bar, universal connecting means ha'v-' ing a portion secured to said bearing means and a portion securable to said supporting means, and V a connecting rod supporting means rigidly secured. to said further bearing means, and means associated with said universal connecting means I to lock said connecting means to secure said fur-' ther bearing means rigidly with respect to said' supporting means. I

3. In a boring apparatus comprising a boring bar, bearing means for said boring bar and supporting means for said bearing means, the provision of a further bearing means adaptable tosaid boring bar, said further bearing means being} adjustable 'to lit and center'it accurately on said" boring bar, universal connecting means having' a' portion secured to said bearing means and a portion securable to said supporting'means, a con; necting rod supporting means rigidly secured to said further bearing means, and adjustable clamping means to secure connecting rods of different sizes in centered relation on said con-" necting'rods'upporting means. V

4. In a boring apparatus comprising a boring bar, a boring tool carried by said boring bar, bearing means for said boring bar and supporting means for said bearing means, the provision of a further'bearing means adaptable to said boring bar','universal connecting means having a portion secured to said bearing means and a portion se curable'to' said supporting means, a connecting rod supporting means rigidly secured to said fur ther bearing means, said connecting rod supporting means having an opening therein for the,

passage, of said boring bar and boring tool therethrough, said connecting rod supporting means also having a face normal to the axis of said bear,-

rate machinev designed and constructed only for.

reboring connecting rods,such as shown in Figs.

' 5, 6 and 7.- Either form of the machine provides forreboring connectingrods of a wide variety of. sizes which may be accommodated by-interchange of the face rings and by swinging'the clamping arms to abut against the outer face of the coning, a face ring having an internal diameter to pass said boring bar and tool and having a portion. of an externaldiameter to fit within said opening of the connecting rod supporting means-and having oppositely therefrom an annular flange with a faceadapted to fit against the face of said con necting rod supporting meansand an end face normal to the axis of said boring bar adapted *to engage a connecting rod, and adjustable clamp,-,

ing means to clamp a connecting rod against said flange in centered relation to said boring bar.

5. A boring apparatus comprising a boring bar, a boring tool carried by said boring bar, bearing means for said boring bar, supporting means for said bearing means, a connecting rod supporting member secured to said bearing means, said connecting rod supporting means having an opening therein for the passage of said boring bar and boring tool therethrough, said connecting rod supporting means also having a face normal to the axis of said bearing, a face ring of an internal diameter to pass said boring bar and tool and having a portion of an external diameter to fit within said opening of the connecting rod supporting means and having oppositely therefrom an annular flange with a face adapted to seat against the face of said connecting rod supporting meansand an end face normal to the axis of said boring bar adapted to engage a connecting rod, and adjustable clamping means to clamp a connecting rod against said flange and centered adjacent to said boring bar.

6. A boring apparatus comprising a boring bar, a boring tool carried by said boring bar, bearing means for said boring bar, supporting means for said bearing means, a connecting rod supporting means secured to said bearing means, said connecting rod supporting means having an opening therein for the passage of said boring bar and boring tool therethrough, said connecting rod supporting means also having a face normal to the axis of said bearing, a face ring of an internal diameter to pass said boring bar and tool and having a portion of an external diameter to fit within said opening of the connecting rod supporting means and having oppositely therefrom an annular flange with a face adapted to fit again-st the face of said connecting rod supporting means and an end face normal to the axis of said boring bar adapted to engage a connecting rod, adjustable clamping means to clamp a connecting rod against said flange and centered adjacent to said boring bar, and feeding means having por- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,967,387 Welke July 24, 1934 2,252,121 Fuglie Aug. 13, 1941 2,349,526 Sunnen May 23, 1944 1,417,278 Peters May 23, 1922 2,015,940 Keller Oct. 1, 1935 1,651,286 Locken Nov. 29, 1927 2,053,644 Tuttle Sept. 8, 1936 g 

